Hot-cathode discharge fluorescent lamp filled with low pressure rare gas

Abstract

Hot-cathode discharge fluorescent lamps filled with low pressure rare gas being discharge fluorescent lamps filled with low pressure rare gas with a tube diameter of 16 mm or less provided with a pair of electrodes on both ends of a glass tube which operate as a hot-cathode in a stable discharge condition, having a fluorescent material layer on the inside surface of the bulb, filled with a luminous gas therein, and which is illuminated with irradiation from discharge in the luminous gas, in which at least one gas of He, Ne, Ar, and Kr are filled in addition to Xe as the luminous gas in an amount that the percentage of additional gas volume to total gas volume exceeds 50%.

What is claimed is: 
     
       1. A hot-cathode discharge fluorescent lamp filled with low pressure rare gas comprising: a tubular glass bulb made of thin glass having fluorescent material layer on an inside surface thereof, and an inner diameter of 16 mm or less; and   a pair of electrodes, one on each end of the tubular glass bulb, at least one of which operates as a hot-cathode at least in a stable discharge condition,   the tubular glass bulb containing a mixture of rare gases, the mixture containing Xe and at least one of He, Ne, Ar and Kr at predetermined pressure values,   the fluorescent material being illuminated with radiation from a discharge in the mixture of rare gases.   
     
     
       2. Hot-cathode discharge fluorescent lamps filled with low pressure rare gas as claimed in claim 1, wherein the percentage of the above mentioned added gases to the total filled gases in volume exceeds 50%.